I'm not a profesionnal translator so there might be some mistakes.
http://game.watch.impress.co.jp/docs...26_703330.html
DRK:
-They wanted to have a different system than the PLD and the WAR. They focused on the theme of the darkness.
-At first they didn't know if they should draw darkness from life, TP or MP, after some tests they chose the MP.
-They won't put PIE on tank gears and DRK will use the same gear PLD and WAR use, just like BLM they resplenish their own MP and don't need to have a big amount of PIE.
-The need of PIE would have made balance issues because DRK would have needed PIE instead of STR or VIT and might become weaker than the other tanks.
-BRD and MCH can't give mana to the DRK when he is in darkness mode because that would have make them dependent of these jobs and create issues while soloing or in DF.
-DRK aren't only dark because they prefer to be alone but also, and you will see it in the job quests, because they are merciless with the corrupt priests.
-The dark and creepy words in all the skills aren't because Yoshida said so but because Nakaji (it might not be reading like that, kanjis are 中二 ) wanted to. Everyone liked it during the presentations. Same goes for the animations and special effects.
MCH:
-The job was remade at the last time, at that time you had to reload for each attack and that was not fun so they changed a lot of thing, now you reload 5 bullets at a time and there is a quick reload for only 1 bullet.
-They also have a caster stance just like the bard, but instead of managing dots they will have to manage the turrets, it may looks a lot like BRD but when you will play, it will feel completely different.
AST:
-They didn't want to break the perfect synergy of the WHM and SCH combo so they added a shield and a pure heal stance to the AST.
-They added improved shield to everyone to keep the balance too.
-It seems that you will be able to control which card you will draw ( Might need some verifications )
For the existing jobs they wanted to fill the holes in the rotations with the new skills.
-For MNK they added that meditation buff so that when the phase change you can remove your greased lightning and use meditation to prepare to go full force when the boss comes back.
-For DRG the blood of the Azure Dragon will make you chose in either increasing the time of the buff or releasing it and inflict a lot of damages, it might be wise to use it all before a phase change so that's it's not running for nothing while the boss is away.
-MNK are more about dealing damage all the time while DRG will deal big spikes of damages in a short time.
-They wanted to add to all the DPS a way to reduce the enmity so they can go easy on the tanks.
-Even if DRG are important in the expansion they will keep the balance between the DPS.
-They wanted to break the umbral ice and astral fire buff rotation for BLM so that is when Enochian enters into the game.
-Ether of Bahamut is a way to fill the time when you spam ruin, you won't be able to have both Aether flow and the ether of Bahamut at the same time, you will first use your ether stacks and then enter Bahamut mode until you can get aether flow again.
-They want to give more pet management to the SMN but for now they focus on the casting part.
-They increased the offensive power of the WHM, not because they want them to be real DPS but because they first didn't expect the players to have the healers DPS in coil, they were surprised to see the top parties do that and they changed their plan. When they do the new raid they now takes healer dps into consideration, that will be a major difference between alexander normal and hard, in the normal mode dps check they don't take into account the healers' damages.
Leveling :
-There will be a new skill every 2 levels, that won't really be faster than 2.0 because lvl 50-60 will be as long as lvl 1-50, so the rythm will be the same.
-Even if there will be a more skills you won't be lost, you won't have to completely remake your action bars, only rearrange it a little.
-They don't think that the 2 weeks before unlocking tomes and alexander is too long, they have to think to the players that don't play a lot.
-You will level your main job by following the main story quests, it will be the most efficient, they calculated that you would go only once or twice in each story dungeon.
-The version presented at Nantes had all the quest hidden to prevent spoilers and informations going out.
Gear :
-The item used are the Yaksha equipments, they are japanese themed because Domans are going to have a big position in Eorzea.
-Yaksha is the equivalent of Darklight, it's ilvl 170, then there are the esoteric gears, Alexander normal and hard gear.
-HM Alexander gear are dyable and stronger than the normal version but the model is the same.
-There won't only be japanese themed gear, there is also a lot of gothic fantasy themed gear.
-You will have new gear in all the dungeons, so you will change every 2 levels. There will be a lot of items in dungeons.
-There will be a lot of gear so you will have a lot of choice for glamour.
-Alphinaud changed his clothes because it is very cold in the north of Eorzea.
Au Ra:
-Men Au Ra emotes looks like happy yound men while women are more shy.
-Women Au Ra were designed to look like the kind of women you want to protect. They didn't plan to have them look like succubus.
-Men were designed to be darker.
-There will only be 1 or 2 new emotes in the 3.0, they want to focus on the gameplay for now but they plan on adding more in the 3.X series.
Dungeons :
-Dungeons will keep the same pattern, they are made for casual players so they don't want to make them longer.
-They are planning a new kind of content where you will feel lost, a lot of players might enjoy these.
-One of the new dungeon is Som Ar ( might be written differently )
-The 8 first dungeons have gimmicks from coil, because they felt that some players didn't know well these gimmicks and that there was issues with sharing damages in WoD as an exemple. Look at this as some kind of catch up for those that didn't go into the Coils.
-It might make players willing to try the coils then.
World:
-There will be wild chocobos, a chocobo hunters village and cute cats with feathers.
-You won't be able to tame the chocobos after beating them.
-First flying will only be about moving but then it will be used to explore, linked to the airship explorations.
-They thought about adding races in the sky where you had to fly through circles, but they didn't have enough time to put this in.
-There will be more dynamic FATEs, just like they did in the fortress in the south shroud where the next fate depends on your victory or your defeat.
-There will be Odin and Behemoth like FATEs too.
-According to the medias, the world is much more dangerous, they tried a FATE and were crushed.
Last words from Yoshida :
The first expansion for FFXIV finally arrive, we are a little late and we are sorry to make you wait for one month. For now the pace is calm we have done most of the work.
Even the european medias said that it is the biggest expansion they have ever seen, we hope that it will come close to your expectations. Until the very end there will be patches, maybe even during early access, we never felt that way since the launch of ARR but we will definitely give you something as big as an average RPG.